Frank Aguilar was shot and killed last November in the West Side neighborhood.
Armando Lopez, 19, is facing a murder charge in the shooting. Prosecutors allege Lopez was driving the night of the fatal drive-by shooting that authorities believe mistakenly targeted Aguilar as a rival.
RELATED: Man, 19, charged with murder after nurse fatally shot in Little Village drive-by
He was arrested four days after the shooting following a police chase and crash.
At the time, Lopez was out on bond for another weapons charge, but community activist Raul Montes Jr. said a judge just acquitted him of that charge.
RELATED: Father of Little Village nurse killed in drive-by shooting speaks
The decision is raising alarms for Aguilar's family, who gathered at the place where he died on Sunday.
Aguilar, a nurse at Misericordia, was carrying in laundry to his sister's Little Village home when he was shot and killed on November 12, 2019.